The trend of expanding the range of the kinds of fuel employed for solving energy problems has become characteristic of many countries, particularly, of industrially developed ones.
There are known guide vane devices of burner arrangements, intended to shape swirling annular flows with a predetermined intensity of the swirl, a predetermined velocity field and a predetermined turbulence degree. Each one of these guide vane devices is characterized by parameters of its action upon the flow, pressure loss, velocity field non-uniformity across the outlet section and the character of this field.
In their turn, these parameters are associated with the geometric dimensions of the components of the guide vane device.
At present, guide vane devices are utilized in combustion arrangements as the means of intensifying the combustion process.
There is known a guide vane device of a burner of the simple tangential type (see, for example, "Burner Devices" by Y. V. Ivanov, in Russian, NEDRA Publishers, Moscow, 1972). The device shapes a flow with a swirl intensity defined by the relationship of the geometric dimensions (the width and length of the feed pipe, the degree of tangentiality of the flow introduced into the swirl chamber, etc.).
By shaping the swirling flow in accordance with the abovelisted dimensions, with moderate pressure loss values (.epsilon.=3 to 5), there is formed by the guide vane device a turbulized flame with the zone of back flows adjacent to the axis, stabilizing the combustion process.
A drawback of the guide vane device of this type is the fixed relationship between the flow characteristics and the geometric dimensions. Besides, the single-side introduction of the flow into the swirl chamber inflicts considerable velocity losses in the areas adjoining the walls, whereby the swirling flow is characterized by significant non-uniformity about the circumference, while the swirl efficiency is inadequate.
There is further known a scroll type guide vane device with a flap-type gate or vane for adjusting the inlet width and the degree of tangentiality of the flow entering the swirl chamber (see, for example, "Blower-Type Gas Burner Devices" by D. N. Akhmedov, NEDRA Publishers, in Russian, Leningrad, 1970).
The incorporation of the flap-type vane in the inlet pipe enables to control the intensity of the swirling of the annular flow within a considerable range, and thus to vary the corresponding characteristics of the flame.
A drawback of the guide vane device of this type is likewise its considerable velocity field non-uniformity, resulting from the single-side introduction of the flow into the swirl chamber.
Moreover, the swirl devices of both abovementioned types are not free from a common drawback, i.e. the impossibility to alter the swirling direction.
There is still further known a guide vane device of a burner providing for controlling both the direction and intensity of the swirling (see, for example, the SU Inventor's Certificate No. 375,447; Int. Cl. F 23 d 17/00, dated 1971).
This guide vane device comprises a cylindrical swirl chamber with equidimensional symmetrically arranged gas inlet ports provided with pivotable vanes or gates. The axles of the pivotable vanes or gates extend along the respective generatrices of the swirl chamber, parallel with the longitudinal axis thereof.
In this device, by varying the position of the pivotable vanes within a broad range, it is possible to vary the width of the gas inlet slits defined by the edges of the vanes and the stationary members of the guide device. This, in its turn, enables to control the intensity of the swirl within a considerable range, as well as the swirl direction. The control range of the flame characteristics of burner arrangements provided with guide devices of this kind is sufficiently wide, with moderate pressure head losses.
A disadvantage of this known guide vane device, however, is the pronounced velocity field non-uniformity and insufficiently effective swirling attained with acceptable head losses.
This can be explained by concentrated introduction of the flow into the swirl chamber, and by the existense of local resistances in the areas where the pivotable vanes adjoin the swirl chamber.